Molded product production device, molded product production method, and molded product

ABSTRACT

A molded product production device that includes a molding die having an inner circumferential surface defining a cavity with upper and lower openings, the cavity into which the molding material is to be filled, a lower punch provided so as to be inserted into the cavity from the lower opening thereof and vertically move, the lower punch having a lower punch surface and a lower punch release agent holding portion which is provided at a lower side of the lower punch surface and capable of holding a release agent, an upper punch provided so as to be inserted into the cavity from the upper opening thereof and vertically move, the upper punch having an upper punch surface, and a lower punch release agent supply means which supplies the release agent to the lower punch release agent holding portion when being exposed outside the cavity.

TECHNICAL FIELD

The present invention relates to a molded product production device, amolded product production method (that is, a method of producing amolded product), and a molded product.

BACKGROUND ART

In general, a molded product production device, which produces a moldedproduct (green compact) by compression molding a powdered moldingmaterial, includes a molding die defining therein a cylindrical cavitywith upper and lower openings and having upper and lower end surfacesdefining the upper and lower openings, respectively, a lower punchhaving a lower punch surface which is to be inserted into the cavityfrom the lower opening of the molding die, and an upper punch having anupper punch surface which is to be inserted into the cavity from theupper opening of the molding die (for example, Patent Document 1).

According to such a molded product production device, for example, in astate that the upper punch is located above the upper end surface of themolding die and the lower punch surface is located into the cavity andbelow the upper end surface of the molding die, the molding material issupplied onto the lower punch surface within the cavity, and then theupper punch surface is moved down so that the molding material iscompression molded using the lower and upper punch surfaces.

Conventionally, in such a molded product production device, for thepurpose of preventing adhesion or bonding of the molding material to thelower and upper punch surfaces and the like, a release agent is appliedonto each of the lower and upper punch surfaces before the moldingmaterial is supplied into the cavity described above.

As described in the Patent Document 1, conventionally, in a state thatthe upper punch is located above the upper end surface of the moldingdie and the lower punch surface is aligned with (is flush with) theupper end surface of the molding die, a nozzle is put between the upperpunch and the lower punch. Thereafter, the release agent is applied ontoeach of the lower and upper punch surfaces by spraying the release agentupward and downward from the nozzle.

However, in the molded product production device according to the PatentDocument 1, the release agent is applied only onto the lower and upperpunch surfaces. Therefore, it is impossible to prevent the moldingmaterial from adhering or bonding to an inner circumferential surfacedefining the cavity of the molding die. This causes quality defects ofan obtained molded product, to thereby raise a problem in thatproductivity thereof is lowered. Such a problem becomes more remarkableif used is a molding material having a high adhesive property, a moldingmaterial having a high shrinkage ratio when being compression molded, orthe like.

PRIOR ART DOCUMENT Patent Document

-   Patent Document 1: WO 2003/037589

OUTLINE OF THE INVENTION

It is an object of the present invention to provide a molded productproduction method and a molded product production device by which amolded product having a high quality can be produced in excellentproductivity, and a molded product having a high quality.

In order to achieve the object described above, the present inventionincludes the following features (1) to (18).

(1) A molded product production device adapted to be used for producinga molded body by compression molding a molding material, comprising:

a molding die having an inner circumferential surface defining a cavitywith upper and lower openings, the cavity into which the moldingmaterial is to be filled;

a lower punch provided so as to be inserted into the cavity from thelower opening thereof and vertically move, the lower punch having alower punch surface and a lower punch release agent holding which isportion provided at a lower side of the lower punch surface and capableof holding a release agent;

an upper punch provided so as to be inserted into the cavity from theupper opening thereof and vertically move, the upper punch having anupper punch surface; and

a lower punch release agent supply means which supplies the releaseagent to the lower punch release agent holding portion when beingexposed outside the cavity.

(2) The molded product production device according to the feature (1),wherein the lower punch release agent holding portion transfers therelease agent held thereto to the inner circumferential surface definingthe cavity as the lower punch moves inside the cavity.

(3) The molded product production device according to the feature (1) or(2), wherein the lower punch release agent supply means supplies therelease agent to the lower punch release agent holding portion whenbeing exposed outside the cavity from the lower opening thereof.

(4) The molded product production device according to any one of thefeatures (1) to (3), wherein the lower punch release agent supply meanssupplies the release agent to the lower punch release agent holdingportion when being exposed outside the cavity from the upper openingthereof.

(5) The molded product production device according to any one of thefeatures (1) to (4), wherein the lower punch release agent supply meansincludes at least one nozzle which injects the release agent toward thelower punch release agent holding portion exposed outside the cavity.

(6) The molded product production device according to any one of thefeatures (1) to (5), wherein before the molding material is filled intothe cavity, the release agent is applied to the lower punch releaseagent holding portion, and then the lower punch is temporarily moved sothat an upper end of a region of the lower punch release agent holdingportion, to which the release agent has been applied, reaches in thevicinity of the upper opening of the cavity.

(7) The molded product production device according to any one of thefeatures (1) to (6), wherein the lower punch release agent holdingportion includes a plurality of concave portions and/or convex portionsformed on an outer circumference of the lower punch.

(8) The molded product production device according to the feature (7),wherein each concave portion is a groove extending along the outercircumference of the lower punch in a horizontal direction.

(9) The molded product production device according to any one of thefeatures (1) to (8) further comprising an upper punch release agentsupply means having a function of applying a release agent to the upperpunch.

(10) The molded product production device according to the feature (9),wherein the upper punch release agent supply means has a function ofapplying the release agent onto each of the upper and lower punchsurfaces.

(11) The molded product production device according to the feature (9)or (10), wherein the upper punch release agent supply means also servesas the lower punch release agent supply means.

(12) The molded product production device according to any one of thefeatures (9) to (11), wherein the upper punch further includes an upperpunch release agent holding portion which is provided at an upper sideof the upper punch surface and capable of holding the release agent, and

wherein the upper punch release agent supply means has a function ofsupplying the release agent to the upper punch release agent holdingportion.

(13) The molded product production device according to any one of thefeatures (1) to (12), wherein an average thickness of the release agentapplied on each of the upper punch surface, the lower punch surface andthe inner circumferential surface defining the cavity is in the range of0.001 to 50 μm.

(14) The molded product production device according to any one of thefeatures (1) to (13), wherein the molding material is of a powderedstate and contains a resin material.

(15) The molded product production device according to the feature (14),wherein the resin material comprises an epoxy-based resin material.

(16) The molded product production device according to the feature (14)or (15), wherein the release agent contains a silicone-based releaseagent.

(17) A method of producing a molded product using the molded productproduction device according to any one of the features (1) to (16),comprising:

a lower punch release agent supply step of supplying the release agentto the lower punch release agent holding portion in a state that thelower punch release agent holding portion is exposed outside the cavity;

a release agent transfer step of transferring the release agent held tothe lower punch release agent holding portion to the innercircumferential surface defining the cavity as the lower punch movesinside the cavity;

a filling step of filling the molding material into the cavity; and

a molding step of compression molding the molding material filled intothe cavity using the upper and lower punches.

(18) A molded product produced using the molded product productiondevice according to any one of the features (1) to (16).

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a sectional view showing the entire structure of a moldedproduct production device according to a first embodiment of the presentinvention.

FIG. 2 is a development view (sectional view) of the molded productproduction device shown in FIG. 1 in a circumferential directionthereof.

FIG. 3 is a partially enlarged sectional view showing the molded productproduction device shown in FIG. 1.

FIG. 4 is a partially enlarged sectional view showing the molded productproduction device shown in FIG. 1, which is continued from FIG. 3.

FIG. 5 is a view for explaining an operation of the molded productproduction device shown in FIG. 1.

FIG. 6 is a view for explaining the operation of the molded productproduction device shown in FIG. 1, which is continued from FIG. 5.

FIG. 7 is a partially enlarged sectional view showing a molded productproduction device according to a second embodiment of the presentinvention.

FIG. 8 is a partially enlarged sectional view showing a molded productproduction device according to a third embodiment of the presentinvention.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinbelow, preferred embodiments of the present invention will bedescribed based on the accompanying drawings.

First Embodiment

First, description will be made on a first embodiment of the presentinvention.

FIG. 1 is a sectional view showing the entire structure of a moldedproduct production device according to the first embodiment of thepresent invention, FIG. 2 is a development view (sectional view) of themolded product production device shown in FIG. 1 in a circumferentialdirection thereof, FIG. 3 is a partially enlarged sectional view showingthe molded product production device shown in FIG. 1 (in the vicinity of120°), FIG. 4 is a partially enlarged sectional view showing the moldedproduct production device shown in FIG. 1 (in the vicinity of 255°) andeach of FIGS. 5 and 6 is a view for explaining an operation of themolded product production device shown in FIG. 1.

In this regard, although a material for sealing semiconductor (powderedresin material) is typically used as a molding material in thisembodiment, the molding material is not limited thereto in the presentinvention. For example, a composition containing various kinds ofinorganic materials or various kinds of organic materials can be used asthe molding material, as long as it can be compression molded to producea molded body (molded product).

A molded body production device (molded product production device) 1according to this embodiment shown in FIG. 1 is a so-called rotary typemolded body production device (tablet machine).

As shown in FIG. 1, such a molded body production device 1 includes aframe 2, a shaft 3 supported by the frame 2 so as to be capable ofrotating about a Z axis, and a rotary table 4 attached to the shaft 3.

To the rotary table 4, a plurality of molding dies 5, a plurality ofupper dies 6 and a plurality of lower dies 7 are attached.

Further, as shown in FIG. 2, an upper die elevating mechanism 8, a lowerdie elevating mechanism 9, an upper die release agent applicationmechanism 10, an ejection guide 11, a molding material supply mechanism12 and a lower die release agent application mechanism 20 are fixedly(unrotatably) provided on the frame 2 around the shaft 3, respectively.In FIG. 2, a position at which cams 82, 92 described below are provided(that is, a position where final compression described below is carriedout) is defined as a reference position (0°), and an angle about an axisline Z is shown.

In such a molded body production device 1, the plurality of molding dies5, the plurality of upper dies 6 and the plurality of lower dies 7rotate about the Z axis together with the rotary table 4. With therotation of the rotary table 4, the upper die elevating mechanism 8moves vertically each upper die 6, and the lower die elevating mechanism9 moves vertically each lower die 7.

On the other hand, each molding die 5 is selectively subjected toapplication of the release agent by the upper die release agentapplication mechanism 10, application of the release agent by the lowerdie release agent application mechanism 20 and filling of the moldingmaterial by the molding material supply mechanism 12, depending on arotation angle thereof.

At this time, each molding die 5 is selectively and sequentiallysubjected to the application of the release agent by the upper dierelease agent application mechanism 10 (that is, this step is a releaseagent application step), the application of the release agent by thelower die release agent application mechanism 20 (that is, this step isa release agent application step), the filling of the molding materialby the molding material supply mechanism 12 (that is, this step is amolding material filling step), compression molding of the moldingmaterial filled into the molding die 5 using the upper die 6 and thelower die 7 (that is, this step is a compression molding step), upwardextrusion of a molded body obtained by the compression molding from themolding die 5 due to moving up of the lower die 7, and ejection of theextruded molded body by the ejection guide 11 (that is, this step is amolded body ejection step).

Hereinbelow, description will be made on each of the componentsconstituting such a molded body production device 1 in detail one afteranother.

The shaft 3 is supported by the frame 2 through bearings 31, 32, 33 sothat it can rotate about the vertical axis line Z.

To a lower end portion of such a shaft 3, a worm wheel 34 is provided(secured). This worm wheel 34 is engaged to a worm 35 which is rotatablydriven by a driving mechanism not shown in the drawings.

Further, to the shaft 3, the rotary table 4 is provided (secured).

The rotary table 4 includes a stage 41 to which the plurality of moldingdies 5 are fixed, an upper die hold portion 42 holding the plurality ofupper dies 6 so as to vertically move and a lower die hold portion 43holding the plurality of lower dies 7 so as to vertically move.

The plurality of molding dies 5 are provided to the stage 41 so as topass through the stage 41 in a vertical direction thereof.

The plurality of molding dies 5 are also provided so that distancestherefrom to the axis line Z are equal to each other (that is, themolding dies 5 are provided at positions each having the samesemidiameter from the axis line Z), and are provided in regularintervals along a circumferential direction about the axis line Z.

Each molding die 5 has a cavity 51 with upper and lower openingstherein.

In this embodiment, the cavity 51 is of a cylindrical shape extendingalong a vertical direction. Namely, a horizontal section of the cavity51 is of a circular shape, and a horizontal section area of the cavity51 is constant in almost all regions of the vertical direction. In thisregard, since a horizontal section shape of the cavity 51 is set basedon a shape of a desired molded body or the like, it is not limited tothe circular shape, but may be an elliptical shape, a polygonal shapeand the like. Further, the horizontal section area of the cavity 51 mayhave a local portion which is expanded or condensed.

Into such a cavity 51, the molding material is supplied (filled) by themolding material supply mechanism 12.

The molding material supply mechanism 12 includes a supply unit 122having a concave portion 121 to which the molding material is suppliedfrom a hopper not shown in the drawings.

This supply unit 122 is provided at a position having the samesemidiameter from the axis line Z as that of the molding dies 5 and at apredetermined position along the circumferential direction about theaxis line Z. Further, the supply unit 122 is capable of sliding withrespect to an upper surface of the stage 41 of the rotary table 4.

The concave portion 121 opens downward.

In such a molding material supply mechanism 12, when the cavity 51 movesbelow the concave portion 121, the molding material supplied in theconcave portion 121 drops toward the cavity 51 to be filled thereinto.

The molding material is not limited to a specific kind as long as it canbe compression molded to thereby obtain a molded body. In the casewhere, for example, a tablet to be used for sealing semiconductor isproduced, a molding material (resin composition) containing a curableresin and a curing agent is used.

Examples of the curable resin include: a novolac-type phenol resin suchas phenol novolac resin, cresol novolac resin or bisphenol A novolacresin; a phenol resin such as resol-type phenol resin; an epoxy resinsuch as a novolac-type epoxy resin (e.g., phenol novolac-type epoxyresin, cresol novolac-type epoxy resin), a bisphenol-type epoxy resin(e.g., bisphenol A-type epoxy resin, bisphenol F-type epoxy resin), ahydroquinone-type epoxy resin, a biphenyl-type epoxy resin, astilbene-type epoxy resin, a triphenol methane-type epoxy resin, analkyl-modified triphenol methane-type epoxy resin, a triazinering-containing epoxy resin, a dicyclopentadiene-modified phenol-typeepoxy resin, a naphthol-type epoxy resin, a naphthalene-type epoxy resinor an aralkyl-type epoxy resin (e.g., phenylene chemical structureand/or biphenylene chemical structure-containing phenol aralkyl-typeepoxy resin, phenylene chemical structure and/or biphenylene chemicalstructure-containing naphthol aralkyl-type epoxy resin); a triazinering-containing resin such as urea resin or a melamine resin; anunsaturated-polyester resin; a bismaleimide resin; a polyurethane resin;a diallyl phthalate resin; a silicone resin; a benzoxazinering-containing resin; a cyanate ester resin; and the like.

One of them can be used alone or two or more of them can be used incombination. Among them, it is preferable to use the epoxy resin.

Further, in the case where the molding material is of a powdered state,a green compact can be obtained using the molded body production device1 as the molded body. Furthermore, in the case where the moldingmaterial is of the powdered state, the powder to be molded has a lowsoftening temperature or the molding material contains an epoxy-basedresin material, the molding material is easy to bond to an upper punchsurface 621, a lower punch surface 721 and an inner circumferentialsurface defining the cavity 51 each described below. Therefore, by usingthe present invention in such a case, the effects thereof can beremarkably exhibited.

On the other hand, examples of the curing agent include an amine-typecuring agent such as an aliphatic polyamine (e.g., diethylene triamine(DETA), triethylene tetramine (TETA), metaxylylene diamine (MXDA)), anaromatic polyamine (e.g., diamino diphenyl methane (DDM), m-phenylenediamine (MPDA), diamino diphenyl sulfone (DDS)), dicyandiamide (DICY) ora polyamine compound containing organic acid dihydrazide; a phenol-typecuring agent (curing agent having phenolic hydroxyl group) such as anovolac-type phenol resin or a phenol polymer; an acid anhydride-typecuring agent such as an aliphatic acid anhydride (liquid acid anhydride)(e.g., hexahydro phthalic anhydride (HHPA), methyl tetrahydro phthalicacid anhydride (MTHPA)) or an aromatic acid anhydride (e.g., trimelliticacid anhydride (TMA), pyromellitic acid dianhydride (PMDA), benzophenonetetracarboxylic acid dianhydride (BTDA)); a polyamide resin and apolysulfide resin.

One of them can be used alone or two or more of them can be used incombination. Especially, in the case where the epoxy resin is used asthe curable resin, it is preferable to use the phenol-type curing agent(curing agent having phenolic hydroxyl group).

In this regard, it is to be noted that the molding material of thetablet to be used for sealing semiconductor may contain a resin otherthan the above curable resin and/or an inorganic filler, or may containvarious kinds of additive agents such as an accelerator, a couplingagent, a coloring agent, a flame retardant, a low stress agent and anantioxidant.

Above such a stage 41 to which the plurality of molding dies 5 aresecured, the upper die hold portion 42 is provided.

To the upper die hold portion 42, the plurality of upper dies 6 areprovided so as to be capable of vertically moving.

The plurality of upper dies 6 are provided so as to correspond to theplurality of molding dies 5 described above. Each upper die 6 isinserted into the cavity 51 of the corresponding molding die 5 from theupper opening thereof.

Namely, the plurality of upper dies 6 are provided at the same distancesas the distances from the above mentioned molding dies 5 to the axisline Z so that the distances thereof are equal to each other (that is,the upper dies 6 are provided at positions each having the samesemidiameter from the axis line Z), and are provided at positions havingthe same pitches as the above mentioned pitches of the plurality ofmolding dies 5 in regular intervals along the circumferential directionabout the axis line Z.

As shown in FIG. 2, each upper die 6 includes an upper die main body 61and an upper punch 62 fitted to the upper die main body 61.

The upper die main body 61 is provided so as to be capable of verticallysliding with respect to the upper die hold portion 42.

To a lower portion of the upper die main body 61, the upper punch 62 isfitted.

The upper punch 62 has an upper punch surface 621 at a lower end thereof(see FIG. 3). This upper punch surface 621 can vertically move and isinserted into the corresponding cavity 51 from the upper openingthereof.

The lower die hold portion 43 is provided so as to face the upper diehold portion 42, by which the plurality of upper dies 6 are held,through the stage 41. Namely, below the stage 41, the lower die holdportion 43 is provided.

To the lower die hold portion 43, the plurality of lower dies 7 areprovided so as to be capable of vertically moving.

The plurality of lower dies 7 are provided so as to correspond to theplurality of molding dies 5 described above. Each lower die 7 isinserted into the cavity 51 of the corresponding molding die 5 from thelower opening thereof.

Namely, the plurality of lower dies 7 are provided at the same distancesas the distances from the above mentioned molding dies 5 to the axisline Z so that the distances thereof are equal to each other (that is,the lower dies 7 are provided at positions each having the samesemidiameter from the axis line Z), and are provided at positions havingthe same pitches as the above mentioned pitches of the plurality ofmolding dies 5 in regular intervals along the circumferential directionabout the axis line Z.

As shown in FIG. 2, each lower die 7 includes a lower die main body 71and a lower punch 72 fitted to the lower die main body 71.

The lower die main body 71 is of a cylindrical shape and is provided soas to be capable of vertically sliding with respect to the lower diehold portion 43.

To an upper portion of the lower die main body 71, the lower punch 72 isfitted.

The lower punch 72 has a lower punch surface 721 at an upper end thereofand a lower punch release agent holding portion 722 formed on a sidesurface of the lower die main body 71 (see FIG. 3).

This lower punch surface 721 can vertically move and is inserted intothe corresponding cavity 51 from the lower opening thereof.

The lower punch release agent holding portion 722 is provided at a lowerside of the lower punch surface 721 (that is, an upper side portion ofthe lower die main body 71) and capable of holding the release agent L.

Such a lower punch release agent holding portion 722 is constructed froma plurality of concave portions 723 and a plurality of convex portions724. This lower punch release agent holding portion 722 transfers therelease agent L held thereto to the inner circumferential surfacedefining the cavity 51 as the lower punch 72 moves inside the cavity 51(in this embodiment, upward).

This makes it possible to apply the release agent L to the innercircumferential surface defining the cavity 51. Therefore, it ispossible to prevent the molding material from adhering or bonding to theinner circumferential surface defining the cavity 51. As a result, theobtained molded body M can have a high quality.

In this embodiment, each concave portion 723 is a groove extending alongan outer circumference of the lower punch 72 in a horizontal direction.On the other hand, each convex portion 724 is a rib provided between theconcave portions 723 and extending along the outer circumference of thelower punch 72 in the horizontal direction.

Further, a cross section shape of each concave portion 723 (groove) isof a rectangle shape. In this regard, it is to be noted that the crosssection shape of each concave portion 723 is not limited thereto, butmay be of a triangular or semicircle shape whose width narrows from anopening side to a bottom side or the like.

Such a lower punch release agent holding portion 722 including theplurality of concave portions 723 and the plurality of convex portions724 formed on the lower punch 72 can hold the release agent L regardlessof being a relatively simple structure. Further, such a lower punchrelease agent holding portion 722 can efficiently transfers the releaseagent L held thereto to the inner circumferential surface defining thecavity 51 at the time of need (specifically, when it is inserted intothe cavity 51).

Each upper die 6 can be vertically moved by the upper die elevatingmechanism 8. Further, each lower die 7 can be vertically moved by thelower die elevating mechanism 9.

The upper die elevating mechanism 8 includes a guide rail 81 and cams82, 83.

The guide rail 81 is provided around the shaft 3 along thecircumferential direction.

This guide rail 81 is configured so as to be engaged to an upper endportion of each upper die 6 described above and change a verticalposition of this engagement portion thereof along the circumferentialdirection. Therefore, with the rotation of the rotary table 4, the guiderail 81 moves vertically each upper die 6.

Each of the cams 82, 83 is provided at an end portion or a predeterminedhalfway portion of the guide rail 81.

Each of these cams 82, 83 has a function of pushing the upper die 6downward.

The lower die elevating mechanism 9 includes a guide rail 91 and cams92, 93, 94.

The guide rail 91 is provided around the shaft 3 along thecircumferential direction.

This guide rail 91 is configured so as to be engaged to a lower endportion of each lower die 7 described above and change a verticalposition of this engagement portion thereof along the circumferentialdirection. Therefore, with the rotation of the rotary table 4, the guiderail 91 moves vertically each lower die 7.

Each of the cams 92, 93, 94 is provided at an end portion or apredetermined halfway portion of the guide rail 91.

Each of these cams 92, 93, 94 has a function of pushing the lower die 7upward. Especially, the cam 92 is provided so as to correspond to (face)the above mentioned cam 82 (through the rotary table 4). Further, thecam 93 is provided so as to correspond to (face) the above mentioned cam83 (through the rotary table 4).

In this way, the cam 82 and the cam 92 are paired. Further, the cam 83and the cam 93 are paired.

As described below, the cams 83, 93 apply pressure for preliminarilycompression molding (preliminarily compressing) the molding materialfilled into the cavity 51 of the molding die 5 to the upper die 6 (upperpunch 62) and the lower die 7 (lower punch 72). Further, the cams 82, 92apply pressure for finally compression molding (finally compressing) themolding material filled into the cavity 51 of the molding die 5 to theupper die 6 (upper punch 62) and the lower die 7 (lower punch 72) afterthe above preliminary compression.

Further, the cam 94 applies pressure for extruding the molded bodyobtained by compression molding outside the cavity 51 to the lower die 7(lower punch 72).

The ejection guide 11 is provided on the stage 41 of the rotary table 4at a latter region with respect to the cam 94 (that is, the right sidein FIG. 2).

This ejection guide 11 is fixedly provided with respect to the frame 2so that it shoves the molded body M extruded from the molding die 5 dueto the pressure of the cam 94 toward a predetermined area outside therotary table 4.

A nozzle 101 of the upper die release agent application mechanism 10 isprovided at a latter region with respect to the ejection guide 11 (thatis, the right side in FIG. 2).

Here, description will be made on the upper die release agentapplication mechanism 10 in detail based on FIG. 3.

This upper die release agent application mechanism 10 can inject therelease agent L toward the above mentioned upper punch surface 621 andinject the release agent L toward the lower punch surface 721.

Especially, this upper die release agent application mechanism (upperpunch release agent supply means) 10 applies the release agent L to eachof the upper punch surface 621, the lower punch surface 721 and theinner circumferential surface defining the cavity 51 before the moldingmaterial is filled into the cavity 51 as described below.

Specifically, the upper die release agent application mechanism 10 isconfigured so as to apply the release agent L onto the upper punchsurface 621 by injecting the release agent L toward the upper punchsurface 621 in a state that the upper punch 62 is located above an upperend surface of the molding die 5 defining the upper opening of thecavity 51, and apply the release agent L onto each of the lower punchsurface 721 and the inner circumferential surface exposing above thelower punch surface 721 by injecting the release agent L toward thelower punch surface 721 in a state that the lower punch surface 721 islocated into the cavity 51 and below the upper end surface of themolding die 5.

In this embodiment, the injection of the release agent L toward theupper punch surface 621 and the injection of the release agent L towardthe lower punch surface 721 are carried out at the same time.

This makes it possible to apply the release agent L to each of the upperpunch surface 621, the lower punch surface 721 and the innercircumferential surface defining the cavity 51 before the moldingmaterial is compression molded. Therefore, it is possible to prevent themolding material from adhering or bonding to each of the upper punchsurface 621, the lower punch surface 721 and the inner circumferentialsurface defining the cavity 51. As a result, occurrence of cord, crackor the like can be prevented in the obtained molded body.

Such an upper die release agent application mechanism (upper die releaseagent injection means) 10 includes, as shown in FIG. 3, a nozzle 101 anda release agent supply device 102.

The nozzle 101 is of a long shape. A distal end portion of the nozzle101 is provided at the same distance as the distances from the moldingdies 5 to the axis line Z, and is provided at a predetermined positionalong the circumferential direction about the axis line Z so as to belocated between the stage 41 and the upper die hold portion 42.

At a distal end portion of the nozzle 101, a nozzle hole (upper nozzlehole) 103 opening upward and a nozzle hole (lower nozzle hole) 104opening downward are formed.

The nozzle hole 103 injects (sprays) the release agent upward, and thenozzle hole 104 is provided so as to be separated from the nozzle hole103 and injects (sprays) the release agent.

Further, a flow path is formed inside the nozzle 101 along alongitudinal direction thereof so as to communicate each of the nozzleholes 103, 104. The flow path is connected to the release agent supplydevice 102 so that the release agent passes therethrough.

In this embodiment, the nozzle 101 is supported by the frame 2 throughan adjustment mechanism not shown in the drawings. In this way, thenozzle 101 can move vertically and change an orientation thereof.

Namely, the upper die release agent application mechanism 10 isconfigured so that the nozzle holes 103, 104 can move vertically andchange orientations thereof.

By vertically moving the nozzle holes 103, 104, it is possible to applythe release agent L to each of the upper punch surface 621, the lowerpunch surface 721 and the inner circumferential surface defining thecavity 51, with optimizing each of a distance between the nozzle hole103 and the upper punch surface 621 and a distance between the nozzlehole 104 and the lower punch surface 721.

Further, by changing the orientations of the nozzle holes 103, 104, evenin the case where molding conditions are changed, it is possible touniformly and reliably apply the release agent L to each of the upperpunch surface 621, the lower punch surface 721 and the innercircumferential surface defining the cavity 51.

The release agent supply device 102 supplies the release agent (releaseagent solution) to the nozzle 101. This release agent supply device 102is not limited to a specific type as long as it can inject the releaseagent from each of the nozzle holes 103, 104. For example, the releaseagent supply device 102 may include a tank in which the release agent isstored, a pump which supplies the release agent stored in the tank tothe nozzle 101 by being pressed, and an adjustment mechanism such as avalve which adjusts the pressure of the pump.

The release agent is selected based on the molding material to be used.Therefore, the release agent is not limited to a specific kind as longas it can exhibit a releasing property with respect to the moldingmaterial. Examples of the release agent include a silicone-based releaseagent such as organopolysiloxane, a fluorine-based release agent such aspolytetrafluorethylene, an alcohol-based release agent such as polyvinylalcohol, waxes such as paraffin, higher fatty acid, higher fatty acidmetal salt, an ester-based wax, a polylefine-based wax, polyethylene andoxidation polyethylene, and the like. One of them may be used alone ortwo or more of them may be used in combination.

Among them, it is preferable to use the silicone-based release agent,and more preferable to use carboxyl-modified dimethyl polysiloxane asthe release agent. Such a release agent has an excellent releasingproperty with respect to the molding material. Therefore, it is possibleto more reliably prevent the molding material from adhering or bondingto each of the upper punch surface 621, the lower punch surface 721 andthe inner circumferential surface defining the cavity 51. Further, thereis a merit in that the release agent hardly has an effect on theobtained molded body.

A character of such a release agent is not limited to a specific type.The release agent can be used as a low viscosity liquid, a highviscosity liquid or a powdered solid. Further, the liquid release agentcan be directly used, or the liquid or solid release agent can be usedby being diluted or dissolved into a solvent.

Such a solvent is not limited to a specific kind as long as it candissolve the release agent thereinto. As the solvent, a general solventsuch as hexane, pentane, hydrofluoro ether or decafluoro pentane can beused. Among them, it is preferable to use the pentane (morespecifically, n-pentane) as the solvent. The pentane has excellentcompatibility with the silicone-based release agent.

Therefore, in the case where a release agent (release agent solution)prepared by dissolving the silicone-based release agent into the pentaneis used, the release agent can be uniformly diluted and sprayed.Further, since the pentane has too high volatility, the solventcontained in the release agent solution can be rapidly vaporized afterthe release agent is sprayed, to thereby prevent the solvent from beingcontaminated into a product (molded body).

In the case where the release agent is a high viscosity liquid having akinetic viscosity at 25° C. measured using an Ubbelohde viscometer being3×10⁻³ m²/s or more or a powdered solid, it is preferred that such arelease agent is used in a state that it is dissolved into the solvent(that is, it is prepared as the release agent solution). In this case,an usage ratio of the release agent to the solvent is not limited to aspecific value as long as the release agent has been dissolved into thesolvent.

The usage ratio of the release agent to the solvent is preferably in therange of 0.01 to 10 wt %, more preferably in the range of 0.05 to 5 wt%, and even more preferably in the range of 0.1 to 3 wt %. This makes itpossible to easily spray the release agent solution using a sprayer orthe like, and to apply the release agent thinly and uniformly.

Further, in the case where the release agent is a low viscosity liquidhaving a kinetic viscosity at 25° C. measured using the Ubbelohdeviscometer being less than 3×10⁻³ m²/s, such a release agent can be useddirectly, but also may be used in a state that it is dissolved into thesolvent (that is, it is prepared as the release agent solution), ifneeded. In this case, the usage ratio of the release agent to thesolvent is not limited to a specific value as long as the release agenthas been dissolved into the solvent.

The usage ratio of the release agent to the solvent is preferably in therange of 0.1 to 50 wt %, and more preferably in the range of 1 to 20 wt%. This makes it possible to apply the release agent thinly anduniformly and to constrict the usage of the solvent.

At a latter region with respect to the nozzle 101 of such an upper dierelease agent application mechanism 10 (that is, the right side in FIG.2), nozzles 201, 202 of the lower die release agent applicationmechanism 20 is provided.

Here, description will be made on the lower die release agentapplication mechanism 20 in detail based on FIG. 4.

This lower die release agent application mechanism 20 supplies therelease agent L to the above mentioned lower punch release agent holdingportion 722 when the lower punch release agent holding portion 722 isexposed outside the cavity.

Such a lower die release agent application mechanism (lower die releaseagent supply means) 20 includes, as shown in FIG. 4, the nozzles 201,202 and a release agent supply device 205.

The nozzles 201, 202 are provided so as to be opposite to each otherthrough the lower punch 72 rotated at a predetermined rotation angle (inthis embodiment, 255°)

At a distal end portion (distal end surface) of the nozzle 201, a nozzlehole 203 is formed. Further, at a distal end portion (distal endsurface) of the nozzle 202, a nozzle hole 204 is formed.

The nozzle holes 203, 203 inject (spray) the release agent,respectively.

A flow path is formed inside the nozzle 201 along a longitudinaldirection thereof so as to communicate the nozzle hole 203. Further, aflow path is formed inside the nozzle 202 along a longitudinal directionthereof so as to communicate the nozzle hole 204. These flow paths areconnected to the release agent supply device 205 so that the releaseagent passes therethrough.

In this regard, it is to be noted that the nozzles 201, 202 may movevertically and change orientations thereof, respectively, like the abovementioned nozzles 101, 102.

The release agent supply device 205 can have the same structure as theabove mentioned release agent supply device 102. Further, the abovementioned release agent supply device 102 may double as the releaseagent supply device 205.

Further, as the release agent of the lower die release agent applicationmechanism 20, the same kind as the release agent used in the upper dierelease agent application mechanism 10 may be used.

Such a lower die release agent application mechanism 20 supplies therelease agent L to the lower punch release agent holding portion 722when the lower punch release agent holding portion 722 is exposedoutside the cavity 51 from the lower end surface of the molding die 5defining the lower opening of the cavity 51, as shown in FIG. 4. Thislower die release agent application mechanism 20 can supply the releaseagent L to the inner circumferential surface defining the cavity 51,while simplifying and downsizing the structure thereof.

The lower punch in which the release agent L is applied to the lowerpunch release agent holding portion 722 is temporarily moved so that anupper end of the lower punch release agent holding portion 722 reachesin the vicinity of the upper opening of the cavity 51 before the moldingmaterial is filled into the cavity 51.

This makes it possible to apply the release agent L to the innercircumferential surface defining the cavity 51 before the moldingmaterial is filled into the cavity 51. Therefore, it is possible toprevent the molding material from adhering or bonding to the innercircumferential surface defining the cavity 51. As a result, theobtained molded body can have a high quality.

Next, description will be made on a molded body production method(molded product production method) of the present invention as oneexample in which a molded body is produced using the molded bodyproduction device 1 constituted as described above.

In the molded body production device 1, each molding die 5 is rotatedtogether with the corresponding upper punch 62 and lower punch 72 withthe rotation of the rotary table 4 about the Z axis. According to therotation angle of the molding die 5, the release agent application step,the molding material filling step, the compression molding step and themolded body ejection step are sequentially carried out.

Namely, the molded body production method using the molded bodyproduction device 1 includes [1] the release agent application step(upper punch release agent supply step), [2] the molding materialfilling step, [3] the compression molding step and [4] the molded bodyejection step.

In this embodiment, the release agent is supplied to the above mentionedlower punch release agent holding portion 722 during the step [2] (thatis, this step is a lower punch release agent supply step), and therelease agent held to the lower punch release agent holding portion 722is transferred to the inner circumferential surface defining the cavityduring the step [4] (that is, this step is a transfer step). The abovesteps [1] to [4] are repeatedly carried out in this order.

Namely, in repeating the above steps [1] to [4], the molded bodyproduction method using the molded body production device 1 includes [A]a lower punch release agent application step (that is, the step [2] inor before the previous time), [B] a release agent transfer step (thatis, the step [4] in or before the previous), [C] the molding materialfilling step (that is, this step is the step [2]) and [D] thecompression molding step (that is, this step is the step [3]).

Hereinbelow, each of the steps will be described in detail one afteranother.

[1] Release Agent Application Step (Upper Punch Release AgentApplication Step)

First, as shown in FIG. 5( a), the release agent L is applied onto eachof the upper punch surface 621, the lower punch surface 721 and theinner circumferential surface defining the cavity 51.

At this time, a rotation angle about the axis line Z of the molding die5, the upper punch 62 and the lower punch 72 is 120°.

Further, the upper punch surface 621 of the upper punch 62 is locatedabove the upper end surface of the molding die 5 due to the action ofthe guide rail 81 of the upper die elevating mechanism 8 (that is, theupper punch surface 621 is away from the upper end surface of themolding die 5). On the other hand, the lower punch surface 721 of thelower punch 72 is located inside the molding die 5 and below the upperend surface thereof due to the action of the guide rail 91 of the lowerdie elevating mechanism 9.

Furthermore, the distal end portion of the nozzle 101 is placed betweenthe upper punch surface 621 and the lower punch surface 721.

Given such an alignment of the molding die 5, the upper punch 62, thelower punch 72 and the nozzle 101, the release agent is injected upward(toward the upper punch surface 621) from the nozzle hole 103 of thenozzle 101 and injected downward (toward the lower punch surface 721)from the nozzle hole 104 of the nozzle 101.

In this way, the release agent injected from the nozzle hole 103 of thenozzle 101 is applied on the upper punch surface 621. Further, since asdescribed above, the lower punch surface 721 of the lower punch 72 islocated inside the molding die 5 and below the upper end surfacethereof, the release agent injected from the nozzle hole 104 is appliedon not only the lower punch surface 721 but also a region where theinner circumferential surface 511 defining the cavity 51 of the moldingdie 5 is exposed above the lower punch surface 721.

In this step, a distance between the lower punch surface 721 and theupper end surface of the molding die 5 when the release agent L isinjected by the upper die release agent application mechanism 10 isdefined as “A” and a distance between the lower punch surface 721 andthe upper end surface of the molding die 5 when the molding material mfilled into the cavity 51 is compression molded using the upper andlower punch surfaces 621, 721 (that is, during the final compression inthe step [3] described below) is defined as “B”, A/B is preferably inthe range of 0.5 to 1.5, and more preferably in the range of 0.7 to 1.2.This makes it possible to more reliably prevent the molding material mfrom adhering or bonding to the inner circumferential surface definingthe cavity 51 after the step [3] described below.

Further, a distance between the lower punch surface 721 and the upperend surface of the molding die 5 when the molding material m is filledinto the cavity 51 (that is, during the quantity adjustment in the step[2] described below) is defined as “C”, A/C is preferably in the rangeof 0.4 to 1.2, and more preferably in the range of 0.5 to 1.0. Thismakes it possible to apply the release agent L on a region of the innercircumferential surface defining the cavity 51 with which the moldingmaterial makes contact.

Further, a thickness (average thickness) of the release agent L appliedon each of the upper punch surface 621, the lower punch surface 721 andthe inner circumferential surface 511 defining the cavity 51 is notlimited to a specific value, but is preferably in the range of 0.001 to50 μm, more preferably in the range of 0.01 to 50 μm, and even morepreferably in the range of 0.05 to 10 μm. This makes it possible toprevent the molding material m from adhering or bonding to each of theupper punch surface 621, the lower punch surface 721 and the innercircumferential surface 511 defining the cavity 51, while preventing amolded body finally obtained from being adversely affected by therelease agent L.

In this regard, the thickness of the release agent L (that is, a layerformed from the release agent L) may be measured using various kinds ofthickness measurement devices, or may be calculated based on a surfacearea of each of the upper punch surface 621, the lower punch surface 721and the inner circumferential surface 511 defining the cavity 51, adilution ratio of the release agent L by the solvent and an applicationamount of the release agent L.

[2] Molding Material Filling Step ([C] Molding Material Filling Step)

Next, the molding material m is filled into the cavity 51.

More sufficiently, first, as shown in FIG. 5( b), the filling of themolding material m into the cavity 51 is started.

At this time, the rotation angle about the axis line Z of the moldingdie 5, the upper punch 62 and the lower punch 72 is 180°.

Further, the upper punch surface 621 of the upper punch 62 is locatedabove the upper end surface of the molding die 5 due to the action ofthe guide rail 81 of the upper die elevating mechanism 8 (that is, theupper punch surface 621 is away from the upper end surface of themolding die 5). On the other hand, the lower punch surface 721 of thelower punch 72 is located inside the molding die 5 and below the upperend surface thereof due to the action of the guide rail 91 of the lowerdie elevating mechanism 9.

Furthermore, the cavity 51 of the molding die 5 moves below the concaveportion 121 of the molding material supply mechanism 12. At this time,the molding material supplied in the concave portion 121 drops towardthe cavity 51 to be filled thereinto.

Thereafter, as shown in FIG. 5( c), the quantity of the molding materialm to be filled into the cavity 51 is adjusted. In this way, the fillingof the molding material m into the cavity 51 is finished.

At this time, the rotation angle of about the axis line Z of the moldingdie 5, the upper punch 62 and the lower punch 72 is 255°.

Further, height (vertical location) of the lower punch surface 721 ofthe lower punch 72 is adjusted so that the quantity of the moldingmaterial becomes a predetermined value due to the action of the guiderail 91 of the lower die elevating mechanism 9.

[A] Lower Punch Release Agent Supply Step

At the same time as the step [2], as shown in FIG. 5( c), the releaseagent L is supplied to the lower punch release agent holding portion722.

More specifically, in the state that the lower punch release agentholding portion 722 is exposed outside the cavity 51, by injecting therelease agent L thereto from the nozzles 201, 202, the release agent Lis supplied to the lower punch release agent holding portion 722.

At this time, in this embodiment, during the step [2], the lower punchrelease agent holding portion 722 is exposed outside the cavity 51 fromthe lower opening thereof.

Further, the distal end portions of the nozzles 201, 202 face the lowerpunch release agent holding portion 722 and are located so as to beopposite to each other through the lower punch 72.

Given such an alignment of the nozzles 201, 202 and the lower punch 72,by injecting the release agent L from the nozzles 201, 202, the releaseagent is applied to the lower punch release agent holding portion 722.

Further, although an application amount of the release agent L to thelower punch release agent holding portion 722 varies depending on aconfiguration of the lower punch release agent holding portion 722, itis not limited to a specific vale, but is preferably substantially equalto or more than a sum volume of the plurality of concave portions 723.This makes it possible to sufficiently hold the release agent to thelower punch release agent holding portion 722 and to reliably anduniformly transfer (supply) the held release agent to the innercircumferential surface defining the cavity 51.

[3] Compression Molding Step ([D] Compression Molding Step)

Next, the molding material m filled into the cavity 51 is compressionmolded using the upper punch 62 and the lower punch 72.

More specifically, first, as shown in FIG. 6( a), the molding material mis preliminarily compression molded (preliminarily compressed) using theupper punch 62 and the lower punch 72.

At this time, the rotation angle about the axis line Z of the moldingdie 5, the upper punch 62 and the lower punch 72 is 315°.

Further, the upper die 6 (upper punch 62) and the lower die 7 (lowerpunch 72) are pressed so as to come close together by the action of thecams 82, 92. In this way, the molding material filled into the cavity 51of the molding die 5 is preliminarily compression molded (preliminarilycompressed).

Thereafter, as shown in FIG. 6( b), the molding material is compressed(finally compressed) by a pressure higher than that of the preliminarycompression using the upper punch 62 and the lower punch 72.

At this time, the rotation angle about the axis line Z of the moldingdie 5, the upper punch 62 and the lower punch 72 is 360° (0°).

Further, the upper die 6 (upper punch 62) and the lower die 7 (lowerpunch 72) are further pressed so as to come closer together by theaction of the cams 82, 92. In this way, the molding material filled intothe cavity 51 of the molding die 5 is finally compression molded(finally compressed).

In this step, the pressure of the upper and lower punch surfaces 621,721 using the cams 82, 92 is not limited to a specific vale, but ispreferably in the range of 150 to 1,000 MPa, more preferably in therange of 250 to 700 MPa, and even more preferably in the range of 300 to600 MPa.

Further, a pressing time of the upper and lower punch surfaces 621, 721using the cams 82, 92 is not limited to a specific vale, but can becontrolled by a rotation speed of the rotary table 4.

Furthermore, a processing temperature of this step is not limited to aspecific value, but is preferably in the range of 15 to 30° C., morepreferably in the range of 18 to 28° C., and even more preferably in therange of 20 to 25° C.

As described above, the molding material m filled into the cavity 51 iscompression molded using the upper punch 62 and the lower punch 72. Inthis way, it is possible to obtain a molded body M.

[4] Molded Body Ejection Step

Next, as shown in FIG. 6( c), the molded body M is ejected from thecavity 51.

More specifically, first, the upper punch surface 621 is moved up abovean upper end of the ejection guide 11, and the lower punch surface 721is moved up so as to be aligned with the upper end surface of themolding die 5.

In this way, the molded body M is extruded outside the cavity 51.

In this state, the extruded molded body M makes close contact with theejection guide 11 with the rotation of the rotary table 4, to thereby beshoved toward the predetermined area outside the rotary table 4.

In this way, the molded body M is ejected from the cavity 51.

[B] Transfer Step

At the same time as the step [4], as shown in FIG. 6( c), the releaseagent L held to the lower punch release agent holding portion 722 istransferred on the inner circumferential surface defining the cavity asthe lower punch 72 moves inside the cavity 51 (upward).

At this time, before the molding material is filled into the cavity 51,the lower punch release agent holding portion 722, to which the releaseagent L has been applied, is temporarily moved so that the upper endthereof reaches in the vicinity of the upper opening of the cavity 51.In this way, the release agent L applied to the lower punch releaseagent holding portion 722 transfers on the inner circumferential surfacedefining the cavity 51.

Especially, after the ejection guide 11 is passed above the cavity 51and before the molding material is filled into the cavity 51, it ispreferred that the upper end of the region of the lower punch releaseagent holding portion 722, to which the release agent L has beenapplied, is temporarily moved in the vicinity of the upper opening ofthe cavity 51. This makes it possible to more reliably apply the releaseagent L on an upper end portion of the inner circumferential surfacedefining the cavity 51.

Further, this also makes it possible to omit the application of therelease agent L on the inner circumferential surface defining the cavity51 by the upper die release agent application mechanism 10. In thiscase, during the above mentioned step [1], the upper punch surface 621may be aligned with (may be flush with) the upper end surface of themolding die 5, or may be located above the upper end surface of themolding die 5.

As described above, the molded body production device 1 (molded bodyproduction method of the present invention) can produce the molded bodyM.

Further, by repeating the above mentioned steps [1] to [4] one afteranother, the molded bodies M can be continuously produced. Further, inthe case where the molded bodies M are continuously produced, the step[1] and the step [A] may be carried out every time or may be carried outonce every several times (several rotations).

According to the molded body production device 1 (molded body productionmethod of the present invention) as described above, it is possible toapply the release agent L to the inner circumferential surface definingthe cavity 51 before the molding material m is compression molded. Thismakes it possible to prevent the molding material m from adhering orbonding to the inner circumferential surface defining the cavity 51. Asa result, the obtained molded body M can have a high quality.

In this way, according to the molded body production device 1 of thepresent invention (molded body production method of the presentinvention), it is possible to obtain a molded body M having a highquality in excellent productivity.

Second Embodiment

Next, description will be made on a second embodiment of the presentinvention.

FIG. 7 is a partially enlarged sectional view showing a molded bodyproduction device according to the second embodiment of the presentinvention.

Hereinbelow, the second embodiment will be described with emphasisplaced on points differing from the first embodiment. No descriptionwill be made on the same points. In this regard, it is to be noted thatthe same reference numbers are applied to the same components shown inFIG. 7 as those of the first embodiment.

A molded body production device 1A of this embodiment includes a lowerdie release agent application mechanism (lower punch release agentsupply means) 20A instead of the upper die release agent applicationmechanism 10 and the lower die release agent application mechanism 20.

This lower die release agent application mechanism 20A supplies therelease agent L to the lower punch release agent holding portion 722when being exposed outside the cavity 51 from the upper opening thereof(above the upper end surface of the molding die 5).

As shown in FIG. 7, such a lower die release agent application mechanism(lower punch release agent supply means) 20A has two nozzles 201A, 202A.

The nozzles 201A, 202A are provided so as to be opposite to each otherthrough near a distal end portion of the lower punch 72 exposed abovethe upper end surface of the molding die 5 and rotated at apredetermined rotation angle (e.g., 255°). In this regard, in thisembodiment, the lower die elevating mechanism 9 of the above mentionedfirst embodiment only has to be controlled so that the distal endportion of the lower punch 72 is exposed above the upper end surface ofthe molding die 5 at the predetermined rotation angle.

At a distal end portion (distal end surface) of this nozzle 201A, anozzle hole 203 is formed. Further, at a distal end portion (distal endsurface) of this nozzle 202A, a nozzle hole 204 is formed.

Such a lower die release agent application mechanism 20A also can applythe release agent L on the inner circumferential surface defining thecavity 51.

Further, in this embodiment, even if the upper die release agentapplication mechanism 10 of the above mentioned first embodiment isomitted, the release agent can be applied on the upper punch surface621, the lower punch surface 721 and the inner circumferential surfacedefining the cavity 51. This makes it possible to reduce the cost of themolded body production device 1A.

Further, the lower die release agent application mechanism 20A has afunction of applying the release agent L to the upper punch 62. Thismakes it possible to prevent the molding material from adhering orbonding with respect to the upper punch 62.

Especially, the lower die release agent application mechanism 20A has afunction of applying the release agent L onto each of the upper punchsurface 621 and the lower punch surface 721. This makes it possible toprevent the molding material m from adhering or bonding with respect tothe upper punch surface 621 and the lower punch surface 721.

The molded body production device 1A according to the second embodimentdescribed above also can exhibit the same effects as the molded bodyproduction device 1 of the above mentioned first embodiment.

Third Embodiment

FIG. 8 is a partially enlarged sectional view showing a molded bodyproduction device according to a third embodiment of the presentinvention.

Hereinbelow, the third embodiment will be described with emphasis placedon points differing from the first embodiment. No description will bemade on the same points. In this regard, it is to be noted that the samereference numbers are applied to the same components shown in FIG. 8 asthose of the first embodiment.

A molded body production device 1B of this embodiment includes an upperpunch 62B and a lower punch 72B.

The upper punch 62B has an upper punch release agent holding portion 622which is provided at an upper side of the upper punch surface 621 andcapable of holding the release agent L.

This upper punch release agent holding portion 622 includes a pluralityof concave portions 625. Such a upper punch release agent holdingportion 622 can transfer the release agent L held thereto to the innercircumferential surface defining the cavity 51 as the upper punch 62Bmoves inside the cavity 51 (in this embodiment, downward). This makes itpossible to more reliably apply the release agent L to the upper endportion of the inner circumferential surface defining the cavity 51.

In this embodiment, each concave portion 625 is of a circular shape at aplanar view thereof. The plurality of concave portions 625 are scatteredon a side surface of the upper punch 62B.

Further, a cross section of each concave portion 625 may be of a shapewhose width is constant from an opening side to a bottom side or may beof a triangular or semicircle shape whose width narrows from an openingside to a bottom side or the like.

To such an upper punch release agent holding portion 622, for example,the release agent is applied by the upper die release agent applicationmechanism 10 of the above mentioned first embodiment.

Further, the lower punch 72B has a lower punch release agent holdingportion 722B which is provided at a lower side of the lower punchsurface 721 and capable of holding the release agent L.

This lower punch release agent holding portion 722B includes a pluralityof concave portions 725. Such a lower punch release agent holdingportion 722B can transfer the release agent L held thereto to the innercircumferential surface defining the cavity 51 as the lower punch 72Bmoves inside the cavity 51 (in this embodiment, upward) like the lowerpunch release agent holding portion 722 of the above mentioned firstembodiment.

In this embodiment, each concave portion 725 is constituted in the samemanner as each concave portion 625 of the above mentioned upper punchrelease agent holding portion 622.

To such a lower punch release agent holding portion 722B, the releaseagent is applied by the lower die release agent application mechanism 20of the above mentioned first embodiment.

The molded body production device 1B according to the second embodimentdescribed above also can exhibit the same effects as the molded bodyproduction device 1 of the above mentioned first embodiment.

While the descriptions are made on the molded product production device,the molded product production method and the molded product according tothe present invention based on the embodiments shown in the drawings,the present invention is not limited thereto. Each componentconstituting the molded body production device or the like issubstituted for an arbitrary component having the same function as it.Further, arbitrary structures also may be added thereto.

For example, the components of each of the above mentioned embodimentsmay be combined with each other.

For example, although the lower punch release agent holding portionincludes the concave portions and the convex portions, a shape of theconcave portion or the convex portion is not limited to one described inthe above mentioned embodiment as long as it can hold the release agentand transfer it to the inner circumferential surface defining the cavityat the time of need.

For example, the lower punch release agent holding portion may be formedon the side surface of the lower punch by a rough surface processingsuch as sandblast.

Further, the lower punch release agent holding portion is not limited tothe structure including the concave portions and the convex portions,but may be formed by, for example, subjecting a treatment for improvinga lyophilic property with respect to the release agent to the sidesurface of the lower punch.

Further, in the description of the above mentioned embodiments, therelease agent is applied to the lower punch release agent holdingportion by being injected (sprayed). However, the release agentapplication method is not limited thereto, but may be carried out by,for example, a method such as a dipping method, an application methodusing a brush, a roller or the like.

INDUSTRIAL APPLICABILITY

A molded product production device of the present invention produces amolded product by compression molding a molding material. Especially,the molded product production device of the present includes a moldingdie having an inner circumferential surface defining a cavity with upperand lower openings, the cavity into which the molding material is to befilled, a lower punch provided so as to be inserted into the cavity fromthe lower opening thereof and vertically move, the lower punch having alower punch surface and a lower punch release agent holding portionwhich is provided at a lower side of the lower punch surface and capableof holding a release agent, an upper punch provided so as to be insertedinto the cavity from the upper opening thereof and vertically move, theupper punch having an upper punch surface; and a lower punch releaseagent supply means which supplies the release agent to the lower punchrelease agent holding portion when being exposed outside the cavity.

This makes it possible to apply the release agent onto the innercircumferential surface defining the cavity. For this reason, it ispossible to prevent the molding material from adhering or bonding to theinner circumferential surface defining the cavity. As a result, theobtained molded product can have a high quality. Therefore, the presentinvention provides industrial applicability.

1. A molded product production device adapted to be used for producing amolded body by compression molding a molding material, comprising: amolding die having an inner circumferential surface defining a cavitywith upper and lower openings, the cavity into which the moldingmaterial is to be filled; a lower punch provided so as to be insertedinto the cavity from the lower opening thereof and vertically move, thelower punch having a lower punch surface and a lower punch release agentholding portion which is provided at a lower side of the lower punchsurface and capable of holding a release agent; an upper punch providedso as to be inserted into the cavity from the upper opening thereof andvertically move, the upper punch having an upper punch surface; and alower punch release agent supply means which supplies the release agentto the lower punch release agent holding portion when being exposedoutside the cavity.
 2. The molded product production device as claimedin claim 1, wherein the lower punch release agent holding portiontransfers the release agent held thereto to the inner circumferentialsurface defining the cavity as the lower punch moves inside the cavity.3. The molded product production device as claimed in claim 1, whereinthe lower punch release agent supply means supplies the release agent tothe lower punch release agent holding portion when being exposed outsidethe cavity from the lower opening thereof.
 4. The molded productproduction device as claimed in claim 1, wherein the lower punch releaseagent supply means supplies the release agent to the lower punch releaseagent holding portion when being exposed outside the cavity from theupper opening thereof.
 5. The molded product production device asclaimed in claim 1, wherein the lower punch release agent supply meansincludes at least one nozzle which injects the release agent toward thelower punch release agent holding portion exposed outside the cavity. 6.The molded product production device as claimed in claim 1, whereinbefore the molding material is filled into the cavity, the release agentis applied to the lower punch release agent holding portion, and thenthe lower punch is temporarily moved so that an upper end of a region ofthe lower punch release agent holding portion, to which the releaseagent has been applied, reaches in the vicinity of the upper opening ofthe cavity.
 7. The molded product production device as claimed in claim1, wherein the lower punch release agent holding portion includes aplurality of concave portions and/or convex portions formed on an outercircumference of the lower punch.
 8. The molded product productiondevice as claimed in claim 7, wherein each concave portion is a grooveextending along the outer circumference of the lower punch in ahorizontal direction.
 9. The molded product production device as claimedin claim 1 further comprising an upper punch release agent supply meanshaving a function of applying a release agent to the upper punch. 10.The molded product production device as claimed in claim 9, wherein theupper punch release agent supply means has a function of applying therelease agent onto each of the upper and lower punch surfaces.
 11. Themolded product production device as claimed in claim 9, wherein theupper punch release agent supply means also serves as the lower punchrelease agent supply means.
 12. The molded product production device asclaimed in claim 9, wherein the upper punch further includes an upperpunch release agent holding portion which is provided at an upper sideof the upper punch surface and capable of holding the release agent, andwherein the upper punch release agent supply means has a function ofsupplying the release agent to the upper punch release agent holdingportion.
 13. The molded product production device as claimed in claim 1,wherein an average thickness of the release agent applied on each of theupper punch surface, the lower punch surface and the innercircumferential surface defining the cavity is in the range of 0.001 to50 μm.
 14. The molded product production device as claimed in claim 1,wherein the molding material is of a powdered state and contains a resinmaterial.
 15. The molded product production device as claimed in claim14, wherein the resin material comprises an epoxy-based resin material.16. The molded product production device as claimed in claim 14, whereinthe release agent contains a silicone-based release agent.
 17. A methodof producing a molded product using the molded product production devicedefined by claim 1, comprising: a lower punch release agent supply stepof supplying the release agent to the lower punch release agent holdingportion in a state that the lower punch release agent holding portion isexposed outside the cavity; a release agent transfer step oftransferring the release agent held to the lower punch release agentholding portion to the inner circumferential surface defining the cavityas the lower punch moves inside the cavity; a filling step of fillingthe molding material into the cavity; and a molding step of compressionmolding the molding material filled into the cavity using the upper andlower punches.
 18. A molded product produced using the molded productproduction device defined by claim 1.